#include <stdio.h>

#include "defs.h"

short *itemset;
short *itemsetend;
unsigned *ruleset;

static unsigned *first_derives;
static unsigned *EFF;

void set_EFF(void)
{
	register unsigned *row;
	register int symbol;
	register short *sp;
	register int rowsize;
	register int i;
	register int rule;

	rowsize = WORDSIZE(nvars);
	EFF = NEW2((nvars * rowsize) + rowsize, unsigned);

	row = EFF;
	for (i = start_symbol; i < nsyms; i++)
	{
		sp = derives[i];
		for (rule = *sp; rule > 0; rule = *++sp)
		{
			symbol = ritem[rrhs[rule]];
			if (ISVAR(symbol))
			{
				symbol -= start_symbol;
				SETBIT(row, symbol);
			}
		}
		row += rowsize;
	}

	reflexive_transitive_closure(EFF, nvars);

#ifdef	DEBUG
	print_EFF();
#endif
}

void set_first_derives(void)
{
	register unsigned *rrow;
	register unsigned *vrow;
	register int j;
	register unsigned mask;
	register unsigned cword;
	register short *rp;

	int rule;
	int i;
	int rulesetsize;
	int varsetsize;

	rulesetsize = WORDSIZE(nrules);
	varsetsize = WORDSIZE(nvars);
	first_derives = NEW2(nvars * rulesetsize, unsigned) - ntokens * rulesetsize;

	set_EFF();

	rrow = first_derives + ntokens * rulesetsize;
	for (i = start_symbol; i < nsyms; i++)
	{
		vrow = EFF + ((i - ntokens) * varsetsize);
		cword = *vrow++;
		mask = 1;
		for (j = start_symbol; j < nsyms; j++)
		{
			if (cword & mask)
			{
				rp = derives[j];
				while ((rule = *rp++) >= 0)
				{
					SETBIT(rrow, rule);
				}
			}

			mask <<= 1;
			if (mask == 0)
			{
				cword = *vrow++;
				mask = 1;
			}
		}

		vrow += varsetsize;
		rrow += rulesetsize;
	}

#ifdef	DEBUG
	print_first_derives();
#endif

	FREE(EFF);
}

void closure(short *nucleus, int n)
{
	register int ruleno;
	register unsigned word;
	register unsigned mask;
	register short *csp;
	register unsigned *dsp;
	register unsigned *rsp;
	register int rulesetsize;

	short *csend;
	unsigned *rsend;
	int symbol;
	int itemno;

	rulesetsize = WORDSIZE(nrules);
	rsp = ruleset;
	rsend = ruleset + rulesetsize;
	for (rsp = ruleset; rsp < rsend; rsp++)
		*rsp = 0;

	csend = nucleus + n;
	for (csp = nucleus; csp < csend; ++csp)
	{
		symbol = ritem[*csp];
		if (ISVAR(symbol))
		{
			dsp = first_derives + symbol * rulesetsize;
			rsp = ruleset;
			while (rsp < rsend)
				*rsp++ |= *dsp++;
		}
	}

	ruleno = 0;
	itemsetend = itemset;
	csp = nucleus;
	for (rsp = ruleset; rsp < rsend; ++rsp)
	{
		word = *rsp;
		if (word == 0)
			ruleno += BITS_PER_WORD;
		else
		{
			mask = 1;
			while (mask)
			{
				if (word & mask)
				{
					itemno = rrhs[ruleno];
					while (csp < csend && *csp < itemno)
						*itemsetend++ = *csp++;
					*itemsetend++ = itemno;
					while (csp < csend && *csp == itemno)
						++csp;
				}

				mask <<= 1;
				++ruleno;
			}
		}
	}

	while (csp < csend)
		*itemsetend++ = *csp++;

#ifdef	DEBUG
	print_closure(n);
#endif
}


void finalize_closure(void)
{
	FREE(itemset);
	FREE(ruleset);
	FREE(first_derives + ntokens * WORDSIZE(nrules));
}


#ifdef	DEBUG
void print_closure(int n)
{
	register short *isp;

	printf("\n\nn = %d\n\n", n);
	for (isp = itemset; isp < itemsetend; isp++)
		printf("   %d\n", *isp);
}

void print_EFF(void)
{
	register int i,
	    j,
	    k;
	register unsigned *rowp;
	register unsigned word;
	register unsigned mask;

	printf("\n\nEpsilon Free Firsts\n");

	for (i = start_symbol; i < nsyms; i++)
	{
		printf("\n%s", symbol_name[i]);
		rowp = EFF + ((i - start_symbol) * WORDSIZE(nvars));
		word = *rowp++;

		mask = 1;
		for (j = 0; j < nvars; j++)
		{
			if (word & mask)
				printf("  %s", symbol_name[start_symbol + j]);

			mask <<= 1;
			if (mask == 0)
			{
				word = *rowp++;
				mask = 1;
			}
		}
	}
}

void print_first_derives(void)
{
	register int i;
	register int j;
	register unsigned *rp;
	register unsigned cword;
	register unsigned mask;

	printf("\n\n\nFirst Derives\n");

	for (i = start_symbol; i < nsyms; i++)
	{
		printf("\n%s derives\n", symbol_name[i]);
		rp = first_derives + i * WORDSIZE(nrules);
		cword = *rp++;
		mask = 1;
		for (j = 0; j <= nrules; j++)
		{
			if (cword & mask)
				printf("   %d\n", j);

			mask <<= 1;
			if (mask == 0)
			{
				cword = *rp++;
				mask = 1;
			}
		}
	}

	fflush(stdout);
}

#endif
